THE TANGANYIKA PROBLEM. 
190 
Described from a single specimen, with the mouth and pharynx full of advanced 
embryos.* 
56. Xenotilapia sima. — Blgr. 1899. (Fig., p. 191, lower.) 
Depth of body 4 times in total length, length of head 3}. Snout very short and 
deep, with very steep convex upper profile ; eye very large, oval, its diameter J 
length of head and much greater than interorbital width ; mouth nearly straight, 
horizontal, extending to below anterior border of eye ; three or four series of scales 
on the cheek ; deciduous scales on the opercle. Gill-rakers very short, broad, 
truncate, nine on lower part of anterior arch. Dorsal XIV. -XV. 12; spines 
subequal from the fifth, £ length of head ; longest soft rays J length of head. 
I’ectoral acutely pointed, as long as head. Ventral with the inner ray produced and 
reaching a little beyond origin of anal. Anal III. n ; third spine J length of head. 
Caudal with deep crescentic notch. Caudal peduncle twice as long as deep. Scales 
3-4 3^=36 
strongly ciliated, 40-41 - Q — ^ ; lat. 1 21 — 22. Pale brownish, with a few round 
15—16 
darker spots ; a blackish opercular spot ; a shining golden spot on the sub-opercle ; 
dorsal greyish, other fins yellowish. 
Total length, 105 millim. 
Described from two specimens. Native name, “Lufuina.” 
57. Xenotilapia ornatipinnis. — Blgr. 1901. (Fig., p. 207, middle.) 
Depth of body nearly equal to length of head, 3J to 3^ times in total length. 
Head quite similar to that of Xenotilapia sima. Fifteen to 17 gill-rakers on lower part 
of anterior arch. Dorsal XIII-XV. 12-13; spines subequal from the fifth or sixth, 
§ length of head. Pectoral pointed, as long or a little longer than the head. 
Ventral not reaching anal. Anal III 7-8 ; third spine } length of head. Caudal 
deeply notched, crescentic. Caudal peduncle i j times as long as deep. Scales 
28—32 
with denticulate border, 34-37 — ; lat. 1 13 — 18. Pale brownish ; a more or less 
4 — 12 
distinct silvery lateral band ; spinous dorsal black-edged ; large blackish spots or 
oblique bars on the dorsal ; upper lobe of caudal edged with blackish ; a chevron- 
shaped blackish band lower down on the caudal, disposed asymmetrically. 
Total length, 1 10 millim. 
Described from several specimens from Kibwesi. 
This species is easily distinguished from Xenotilapia sima by the shorter body, 
the fewer anal rays, and the lower number of scales in a longitudinal series. 
The skeleton of Xenotilapia is very similar to that of Ectodus. There are 
likewise three low crests on the back of the skull, the vertebra; number 13+22 in 
Xenotilapia sima, 14 + 20 in Xenotilapia ornatipinnis, and the ribs are remote from 
the centres. 
* Further details of the characters of this genus are given by Mr. Boulenger from 
additional specimens brought home by me on the second Tanganyika expedition. — 
Trans. Zoo. Soc. Lon., Vol. xvi., Part 3, p. 154, from which a second figure of the 
species is given on p. 175 present work. 
